Abstract: A portable fall prevention apparatus. The apparatus provides points of attachment for a tether line to which a safety harness worn by a workman on a sloped roof can be attached. A pair of grapples attach to opposite, overhang portions of a sloped roof. A tie down strap threaded through a ratchet tie down connects each of the grapples to oppositely-disposed, oppositely-directed hinge plates of an anchor assembly. With the anchor assembly placed transversely across the ridge of a sloped roof and the tie down straps tightened to eliminate slack therein, the anchor assembly provides a secure point of attachment for a tether line.